In the first episode of Ping Pong the Animation, around 9 minutes in, Peco called Smile a poster child for B type blood. What does this mean, exactly? What significance does this have? How does this relate to his personality?

@キルア I would vote as duplicate. The answer fits this question, and the Japanese culture around blood types has no relation to the anime in hand.
– MindwinApr 4 '15 at 1:33

@Mindwin Except that the character in the show will have some, but not necessarily all, of the traits in question. The traits Smile shows may also not show direct overlap with any of the B-type traits in that question. Knowledge of the character in Ping Pong would basically be required to answer this properly.
– KilluaApr 4 '15 at 1:34

1 Answer
1

Blood type carries a significant weight in Japanese culture, so much so that Japanese are often surprised when people of other origins are not familiar with their blood type. In their culture, they associate every blood type with a certain personality and demeanor.

The definition of "poster child" has since been expanded to a person of any age whose attributes or behaviour are emblematic of a known cause, movement, circumstance or ideal. Under this usage, the person in question is labeled as an embodiment or archetype. This signifies that the very identity of the subject is synonymous with the associated ideal; or otherwise representative of its most favorable or least favorable aspects.

Yutaka Hoshino/Peco (星野 裕/ペコ Hoshino Yutaka/Peko)
One of the protagonists and Smile's childhood friend. Peco is loud, cocky, and carefree. He is initially considered one of the best players on the Katase team, but begins questioning himself after a couple of surprising losses. Peco is frequently seen snacking on various junk food items.

So he is saying something in the lines of

"you could put a picture of Peco in the encyclopedia entry for blood type B's personality."
or